Search results
Results from the WOW.Com Content Network
Worker at carbon black plant, 1942. Carbon black (with subtypes acetylene black, channel black, furnace black, lamp black and thermal black) is a material produced by the incomplete combustion of coal tar, vegetable matter, or petroleum products, including fuel oil, fluid catalytic cracking tar, and ethylene cracking in a limited supply of air.
Typically, black carbon accounts for 1 to 6%, and up to 60% of the total organic carbon stored in soils is contributed by black carbon. [31] Especially for tropical soils black carbon serves as a reservoir for nutrients.
Bituminous coal has a composition of about 84.4% carbon, 5.4% hydrogen, 6.7% oxygen, 1.7% nitrogen, and 1.8% sulfur, on a weight basis. [11] This implies that chemical processes during coalification remove most of the oxygen and much of the hydrogen, leaving carbon, a process called carbonization. [26]
Charcoal is a lightweight black carbon residue produced by strongly heating wood (or other animal and plant materials) in minimal oxygen to remove all water and volatile constituents. In the traditional version of this pyrolysis process, called charcoal burning, often by forming a charcoal kiln , the heat is supplied by burning part of the ...
Carbon black is hydrophobic, meaning it doesn’t mix with water. So, when added to wet cement, it clumps up into strands and voids between pockets of the goopy substance. In doing so, the carbon ...
Carbon black particle size is between 10 and 100 nm, while the surface particle size is between 20 and 1,500 m 2 /g. Generally speaking, small carbon black particles with a high surface area are darker, have higher viscosity and lower wettability, are harder to disperse, retain greater conductivity and absorb UV radiation well. [1] [2] [3] [7] [8]
Black carbon can absorb sunlight and reduce albedo when deposited on snow and ice. Indirect heating can be caused by the interaction with clouds. [ 105 ] Black carbon stays in the atmosphere for only several days to weeks. [ 106 ]
The black numbers indicate how much carbon is stored in various reservoirs, in billions tonnes ("GtC" stands for gigatonnes of carbon; figures are c. 2004). The purple numbers indicate how much carbon moves between reservoirs each year.